柔性电路微波快速表面贴装技术实验研究

Experimental Study on Rapid Microwave Surface Mounting Technology for Flexible Circuits

集成电路元件表面贴装于柔性基底的混合式柔性电路具有广泛的应用前景和快速商业化潜力,但大部分柔性电路不耐高温,如何将集成元件通过选择性加热,将其快速、大规模、牢固地贴装到柔性电路上成为了限制其发展的难题。为此,本文提出利用微波磁场对金属粉末的选择性加热特性,实现柔性电路上表面贴装元件的快速高效贴装。利用TE 102微波单模谐振腔加热实验,将零欧电阻和贴片LED快速贴装在聚酰亚胺柔性电路上,验证了微波快速高效表面贴装的可行性。通过对比微波快速加热和传统加热方式处理焊点的微观结构发现:微波处理的样品具有更薄的金属间化合物厚度,有利于提高焊点强度。本文提出的微波磁场表面贴装技术为柔性电路表面元件的快速大规模贴装提供了方案,有利于推动柔性电路的发展和商业化。

Hybrid flexible electronics with integrated circuit components mounted on flexible substrates have wide application prospects and commercialization potential.However,most of the flexible circuits are not resistant to high temperature,and it is a great challenge to mount the electronic components on temperature sensitive flexible substrates firmly and rapidly without damaging the substrate,which restrains the development of the hybrid flexible electronics.Microwave magnetic field is utilized to realize rapid and efficient component surface-mounting on flexible circuits,because it can quickly and selectively heat metallic powders.In a TE102 single mode cavity experiment,chip resistors and patch light emitting diodes(LEDs)are quickly mounted on polyimide flexible substrate,verifying the feasibility of microwave fast and efficient surface mounting.By comparing the microstructure of solder joints treated by microwave heating and by traditional heating,it is found that the former has thinner intermetallic compound thickness,which can improve the strength of solder joint.The proposed microwave magnetic field surface mounting technology provides a solution for the rapid and large-scale mounting of surface components in flexible circuits,which is conducive to promoting the development and commercialization of flexible circuits.